1. Field of the Invention
The present invention concerns a composition for dermatological application effective for use in treatment of liver-spots, freckles, pigmentations, acnes, etc. and is based on the novel pharmacological discovery that certain dicarboxylic acid esters exhibit properties useful in such treatment.
2. Description of the Prior Art
It is known that dicarboxylic acids, their reductive derivatives and salts thereof are pharmacologically effective in treatment of chromatopathia such as liver-spots, freckles, etc. When these dicarboxylic acids are to be used as a pharmacological composition for dermatological application, they are found to be extremely inferior in their solubility in fats and oils. Therefore, there are considerable difficulties in preparing them into various dosage forms. Moreover, they tend to be instable as they become crystallized and separated with the passage of time. Accordingly, the tendency is that there are problems for dicarboxylic acids to manifest their original pharmacological actions, and for obtaining preparations of satisfactory properties. Although their salts improve the water dispersing property and therefore makes pharmaceutical preparation easier, they tend to cause irritation to the skin if applied carelessly depending on the degree of neutralization because of their property as a soap. This may cause problems in safety, and discomfort in use. It may at times inhibit the above mentioned effects. There are approximately same problems as regards the reductive derivatives of dicarboxylic acids. These problems and difficulties have not yet been solved.